MscL Research Articles

In vivo Slit Scanning Confocal Microscopic Observation in a Patient with Keratoconus Wearing Miniscleral Contact Lens for One Year: A Case Report

The purpose of the present case report was to evaluate corneal microstructure in a patient with keratoconus wearing miniscleral contact lens (MS CL) for 1 year. A 38 years old patient diagnosed with stage III keratoconus in right eye and corneal graft (penetrating keratoplasty) in left eye was referred to optometry department of a public hospital in Malaysia. Based on the MS CLs fitting performance on the patient’s eye, MS CLs were prescribed in both eyes. However, patient opted for MS CL only in the right eye. In vivo slit scanning confocal microscopy was performed at baseline and after 1 year of contact lens wear in right eye. Qualitative analysis was done using a grading scale designed by Hollingsworth et al. (2005a), while quantitative analysis was performed using NAVIS software in a fixed frame of 0.06 mm². After 1 year of MS CL wear, qualitative observation of right cornea showed no change in stromal haze and architecture of nerve fibers. However, morphological alterations like dark bands were observed both in anterior and posterior stroma along with tendency of clustering keratocyte nuclei in posterior stroma. Quantitative analysis showed that anterior and posterior stroma keratocyte density and endothelium cell density were relatively low after 1 year of MS CL wear (817.3, 667.2, and 2577 cells/mm², respectively) caompared to baseline observation (850.7, 705.0, and 2666 cells/mm², respectively). Mean cell area of anterior stroma, posterior stroma and endothelium were also different in post MS CL wear. Polymegathism and pleomorphism calculated by NAVIS software were varied after 1 year (49.6% and 37.5%, respectively) compared to baseline (67.1% and 29.6%, respectively). In the discussed case, noticeable changes were observed in corneal microstructure after 1 year of MS CL wear. Thereby, in conclusion we recommend future studies with more number of keratoconic eyes wearing MS CLs to emphasize the findings on microstructural changes in keratoconic cornea wearing MS CLs.

2P047 大腸菌機械受容チャネルMscLの開口における脂質膜環境に影響される脂質-タンパク質間相互作用の解析(01B. 蛋白質:構造機能相関,ポスター,第52回日本生物物理学会年会(2014年度))

2P047 大腸菌機械受容チャネルMscLの開口における脂質膜環境に影響される脂質-タンパク質間相互作用の解析(01B. 蛋白質:構造機能相関,ポスター,第52回日本生物物理学会年会(2014年度))

Maestro di Pico i iluminacije u inkunabuli De Civitate Dei (Nicolas Jenson, Venecija, 1475.) u samostanu Sv. Duje u Kraju na Pašmanu

Maestro di Pico i iluminacije u inkunabuli De Civitate Dei (Nicolas Jenson, Venecija, 1475.) u samostanu Sv. Duje u Kraju na Pašmanu

Chlorine and sodium chemical shift imaging during acute stroke in a rat model at 9.4 Tesla

A triple-resonant coil setup with an (1)H linear resonator and a double-tuned (23)Na/(35)Cl surface coil was used to study the evolution of T 2 (*) and M 0 for (35)Cl and (23)Na in a rat stroke model during the acute phase at 9.4 Tesla. In vivo measurements were performed 1.5-7 h after onset of stroke (n = 2), ten days after onset (n = 1) and on a healthy control rat by a chemical shift imaging sequence. Measurement times were 15 min ((23)Na) and 57 min ((35)Cl). The relaxation times ten days after onset [T 2 (*) = 14.3 ± 1.8 ms ((23)Na) and 6.0 ± 1.3 ms ((35)Cl)] are clearly prolonged in comparison to a healthy rat [T 2 (*) = 4.8 ± 0.6 ms ((23)Na) and 2.1 ± 0.3 ms ((35)Cl)] and the acute phase [T 2 (*) = 5.6 ± 0.2 ms ((23)Na) and 1.9 ± 0.1 ms ((35)Cl)]. M 0 in the infarcted region clearly rises later and slower for chlorine than for sodium. To the best of our knowledge, these are the first combined proton, sodium, and chlorine measurements in an animal stroke model during the acute phase.

On-line high-performance liquid chromatography–diode array detection–electrospray ionization–mass spectrometry–chemiluminescence assay of radical scavengers in Epimedium

An on-line analysis method for the simultaneous detection and identification of radical scavenging compounds in plant extracts was developed by combining HPLC with hydrogen dioxide radical scavenging and HPLC–DAD–MS–CL system. The structural identification and activity characteristics of various constituents could be rapidly achieved by the on-line assay of UV, MS and CL in one run. In 4 species of Epimedium studied 32 compounds, including phenolic acids, 8-isopentenyl-flavonoid glycosides and flavonoid glycosides containing a ortho-hydroxyl group, were identified by comparison with authentic standards and published mass data. Among these compounds, phenolic acids and flavonoid glycosides containing an ortho-hydroxyl group could obviously inhibit CL, which suggested their strong radical scavenging activity. These four species each exhibited different active properties, which might correlate to their respective quality. The results indicated that the on-line HPLC–DAD–MS–CL system would be a potential method to rapidly and sensitively screen radical scavengers in herbal medicines, and could display an integrated fingerprint based on different detectors.

Basic EPS: How to Differentiate the Mechanisms of Narrow and Wide Complex Tachycardias?

A systematic approach to differentiate tachycardia of narrow and wide complex QRS morphology includes physical signs/symptoms, simple ECG criteria, pharmacologic and stimulation maneuvers in the EP lab. If narrow QRS duration ( 100 bpm in adults) is shown on 12 lead ECG, then additional ECG criteria such as RR regularity, RP/PR relation, onset/offset of tachycardia and response to vagal maneuvers or adenosine is examined to differentiate between AVNRT, pathway mediated tachycardia or atrial tachycardia. If wide complex tachycardia (WCT) is shown, then QRS morphology (compared with sinus), evidence of AV dissociation, QRS concordance pattern, fusion/capture beats are useful to differentiate if WCT is SVT with aberration, VT or preexcited tachycardia. Stimulation maneuvers include response of tachycardia to extrastimului, reset response to entrainment pacing. A His-refractory PVC delivered into SVT that is able to advance retrograde atrial activation timing with the same tachycardia sequence and resets or terminates tachycardia is diagnostic proof of a pathway mediated SVT and excludes AVNRT. A delta-VA of <85 ms or PPI-Tachy CL of <115 ms after ventricular entrainment pacing favors pathway mediated SVT over AVNRT. Post pacing VAAV response is more consistent with atrial tachycardia. Measurement of the HV interval during WCT helps to differentiate the mechanism, HV that is the same or longer than in sinus is consistent for SVT with aberration.

Non-catalytic role of carbonic anhydrase in rat intestinal absorption

Carbonic anhydrase (CA) inhibition reduces NaCl absorption in rat distal ileum, a pH-sensitive, low CA activity tissue, and in distal colon, a CO 2-sensitive, high CA activity tissue. We hypothesized that CA plays a non-catalytic role in NaCl absorption in these segments. Unidirectional fluxes of Na + and Cl −, and total HCO 3 − generation (estimated as the sum of radiolabeled HCO 3 − and CO 2 produced from glucose) were measured in Ussing chambers in nominally CO 2, HCO 3 −-free HEPES Ringer. Measurements were made in the presence and absence of 0.1 mM methazolamide, a membrane-permeant CA inhibitor. Ringer pH reduction from 7.6 to 7.1 stimulated ileal but not colonic Na + and Cl − absorption. In the ileum, methazolamide reduced J ms Na and J ms Cl and caused net Cl − secretion at pH 7.6, and prevented the stimulatory effect of lowering pH. In the colon, methazolamide reduced Na + and Cl − absorption at pH 7.6. Total HCO 3 − generation was minimal in HEPES at pH 7.6 and 7.1 in both segments, was minimally affected by methazolamide, and did not account for the changes in Cl − absorption caused by pH or methazolamide. We conclude that CA plays a role in ileal and colonic NaCl absorption independent of its catalytic function.

960-84 Ramdomized Prospective Comparison of Four Burst Pacing Algorithms for Spontaneous Ventricular Tachycardia

Burst antitachycardia pacing (ATP) is higly efficacious for termination of monomorphic ventricular tachycardia (MVT). Since several pacing sequences are usually programmed as a single therapy. optimal programming is presently unknown. In 40 patients (P) with MVT and a 3rd generation AICD, 4 burst ATP were prospectively compared (as afirst single ATP) during followup in a randomized design crossing over every 2–3 months. Burst ATP modes (A to D) were defined by pacing cycle length (PCL, as % of VTCL) and number of beats (No B) (Table). A second ATP zone was programmed in a non selected way in all patients 374 episodes (317 considered MVT) received ATP therapies in 23 patients. RR intervals could be retrieved for MVT-CL analysis in 168 episodes. Succes rate of combined first (randomized) and second (non selected) therapies was 92%. Acceleration rate estimation was 2%.TherapyABCDglobalpPCL/No B91/781/791/1581/15AllVT68%46%85%61%69%&lt;0.001VTCL &lt; 350*82%14%44%38%47%0.03VTCL&gt; 350°73%100%91%86%90%ns*Cl &lt; 350: group of Mvr with Cl &lt; 350 ms°Cl &gt; 350: Mvr with Cl &gt; 350 ms Cl &lt; 350: group of Mvr with Cl &lt; 350 ms Cl &gt; 350: Mvr with Cl &gt; 350 ms 1. Efficacy of the tested burst pacing modes differs significantly, at least in fast VT. 2. Contrary to what could be expected. “less agressive” bursts seem to be more efficacious, even in fast VT.

A large-conductance mechanosensitive channel in E. coli encoded by mscL alone.

All cellular organisms respond to vibration, touch, gravity or changes in osmolarity, although the molecules on which such mechanosensations depend are unknown. Candidates include certain channels that gate in response to membrane stretch. Patch-clamp experiments with Escherichia coli envelope have revealed a mechanosensitive channel with very large conductance (MscL) and one with a smaller conductance (MscS) which may be important in osmoregulation. Here we have solubilized and fractionated the envelope, reconstituted the MscL activity in vitro, and traced it to a small protein, whose gene, mscL, we then cloned. Insertional disruption of mscL removes the channel activity, whereas re-expression of mscL borne on an expression plasmid restores it. MscL-channel activities were observed in material from a cell-free expression system with mscL as the only template. The mscL nucleotide sequence predicts a unique protein of only 136 amino acids, with a highly hydrophobic core and very different from porins or other known proteins.

Nacl flux in the flounder ( Pseudopleuronectes americanus) intestine: Effects of ph and transport inhibitors

1. 1. The effects of extracellular pH on Na + and Cl − absorption were studied in vitro in the small intestine of the winter flounder, Pseudopleuronectes americanus. 2. 2. Reductions in bathing solution pH inhibited J ms na (mucosal-to-serosal flux) and J net na (net flux) ( r = 0.90) and J net Cl ( r = 0.92) [due to an increase in J sm Cl, (serosal-to-mucosal)] and decreased short circuit current (Isc). 3. 3. Luminal bumetanide (0.1 mM) and amiloride (1 mM) inhibited Na + and Cl − absorption by reducing J ms. 4. 4. Luminal barium (5mM) and luminal copper (100 μM) decreased J ms Cl and increased J sm Cl. 5. 5. We conclude that reductions in extracellular pH inhibit a luminal membrane NaCl absorptive process (Na +-K +-2Cl −) and stimulate an electrogenic Cl − secretory process.

Mechanisms of sodium and chloride transport across isolated sheep reticulum

1. 1. 22Na + and 36Cl − fluxes across isolated reticular epithelium of sheep were measured by using the Ussing-chamber technique. 2. 2. Net NaC1 absorption driven by Na +-K +-ATPase was observed under short-circuit conditions. 3. 3. Evaluation of fluxes measured under voltage-clamp conditions indicated that Na + absorption is mainly electroneutral. 4. 4. Mucosal application of bumetanide, hydrochlorothiazide, or low dose amiloride (10 − 4 M) produced no changes in Na + transport whereas addition of higher doses of amiloride (⩾10 −3 M) led to a reduction in net Na + transport. Short chain fatty acids (SCFA) enhanced the amiloride-sensitive Na + transport. 5. 5. Alterations of J ms na induced by inhibitors or by SCFA were always accompanied by qualitatively similar changes of J sm na. Amiloride-sensitive J sm na was also decreased at low mucosal Na + concentration. 6. 6. DIDS, SITS, and nitrate reduced both J ms cl and J sm cl. SCFA did not influence chloride transport. 7. 7. It is concluded that Na + transport is mediated by Na +-H + exchange and by transport processes operating as Na + self-exchange. Mucosal-to-serosal chloride transport seems partly to depend on anion exchange systems.

In vitro studies of theophylline-induced changes in Na, K and Cl transport in hen ( Gallus domesticus) colon suggesting bidirectional, basolateral NnK2Cl cotransport

1. 1. In isolated mucosa from a NaCl-loaded hen theophylline stimulates both unidirectional chloride fluxes (J Cl msand J Cl ms). Conductive and electroneutral exchange processes, besides a bumetanidesensitive, rheogenic process contribute. 2. 2. The bumetanide-sensitive fraction of the theophylline-induced ΔJ Cl ms is sodium-dependent. 3. 3. Incubation in nominally K +-free solutions reduces the bumetanide-sensitive fraction ΔJ Cl ms more than treatment with ouabain. 4. 4. With respect to chloride the bumetanide-sensitive fraction of ΔJ Cl ms has a Hill coefficient of 1.93 ± 0.03, a J max of 12.9 ± 0.2 μ mol/cm 2· hr and a K 1 2 of 73 ± 1 mmol/l . 5. 5. After ouabain treatment ΔJ ms Cl and ΔJ ms Cl are equally sensitive to bumetanide, while ΔJ ms Cl is bumetanide insensitive without ouabain treatment.